Power balance module suitable for seabed observation network

Abstract

The invention discloses a power balance module suitable for a seabed observation network, an input side is connected with a main power conversion module of an underwater power supply, an output end is connected with a post-stage junction box, and the power balance module comprises a sampling unit which is used for collecting total current output by the main power conversion module at constant voltage and outputting collection parameters for closed-loop control of each power conversion module; the power distribution unit distributes the total current output by the underwater power supply to the power conversion unit and performs fault isolation; the plurality of power conversion units form series or parallel hot backup redundancy according to different connections of the power distribution units, and power dissipation is balanced in cooperation with a current sharing algorithm; each working power conversion unit quantitatively extracts power from the underwater power supply and supplies the power to the balance load for dissipation, and after the actual load is connected, converted electric energy is reduced in real time, the dissipation power of the balance load is reduced, and it is guaranteed that the output power of the underwater power supply is kept balanced; the balance load receives the electric energy output by the power conversion unit, converts the electric energy into heat energy and dissipates the heat energy through seawater.

Description

Technical Field

[0001] The present invention belongs to the technical field of subsea observation networks, and particularly relates to a power balance module applicable to subsea observation networks. Background Art

[0002] The high-voltage DC power supply network of the subsea observation network consists of an onshore high-voltage power supply, a submarine cable, an underwater medium-voltage conversion power supply (hereinafter referred to as the underwater power supply), and a junction box. The onshore high-voltage power supply converts the commercial power into high-voltage direct current of tens of thousands of volts, and the submarine cable transmits the high-voltage direct current to the underwater power supply hundreds of kilometers away. The underwater power supply converts the high-voltage direct current into medium-voltage direct current required by scientific instruments (hereinafter referred to as actual loads). As the load of the underwater power supply, the junction box distributes the medium-voltage direct current to scientific instruments through each port, and it can communicate with the onshore control center through the optical fiber inside the submarine cable and is controlled by onshore equipment. Due to the influence of the transmission line effect of the submarine cable during the long-distance transmission of high-voltage direct current, the output power of the underwater power supply needs to remain constant or change with a small power, otherwise it will cause the power supply system to oscillate and collapse.

[0003] In the Chinese patent application "A Constant-Power Underwater Power Supply with Self-Matching Power and Its Power Supply Method" with the publication number CN111404142A, a constant-power type underwater power supply with constant-current power supply is mentioned, which uses a power balance module to maintain the total power balance of the system.

[0004] This design has the following problems: 1. The power balance module is deeply coupled with the main power conversion part of the underwater power supply, without redundant backup, and there is a risk of single-point failure. 2. The power point at which the power balance module operates is not adjustable and always operates at full load to maintain the maximum power output, resulting in additional energy waste.

[0005] Therefore, based on the requirements of the subsea observation network for a constant-power, highly reliable, and high-power underwater power supply, there is an urgent need for a power balance module with high redundancy, adjustable power, and suitable for long-distance and high-power underwater power supplies. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and propose a power balance module applicable to subsea observation networks.

[0007] In view of this, the present invention proposes a power balance module applicable to subsea observation networks. The input side is connected to the main power conversion module of the underwater power supply, and the output end is connected to the subsequent junction box. It includes: a sampling unit, a power distribution unit, and multiple power conversion units deployed on a board, as well as a balancing load. Among them,

[0008] The sampling unit is used to collect the total current of the constant-voltage output of the main power conversion module of the underwater power supply and output the collected parameters for closed-loop control of each power conversion module;

[0009] The power distribution unit is used to distribute the total current output by the underwater power supply to each power conversion unit and isolate a certain power conversion unit in case of its failure.

[0010] The multiple power conversion units are used to form a series or parallel type hot standby redundancy according to different connection modes of the power distribution unit, and cooperate with the current sharing algorithm to balance the power dissipation; each working power conversion unit quantitatively extracts power from the underwater power supply and supplies it to the balancing load for dissipation. When the actual load is connected, the converted electric energy is reduced in real time, and the power dissipation of the balancing load is reduced to ensure that the output power of the underwater power supply remains balanced.

[0011] The balancing load is used to receive the electric energy output by the power conversion unit, convert it into heat energy and dissipate it through seawater.

[0012] Preferably, the sampling unit adopts a sampling resistor or a Hall element.

[0013] Preferably, the power distribution unit realizes the distribution function by using a switching network. In the series mode, the switching network is composed of a short - circuit switch and a short - circuiting switch. In the parallel mode, the switching network is composed of power access switches, where,

[0014] The short - circuit switch is used to connect each power conversion unit in series in turn;

[0015] The short - circuiting switch is used to short - circuit the input port of the power conversion unit;

[0016] The power access switch is used to connect the power conversion unit to the DC bus;

[0017] The short - circuit switch, the short - circuiting switch and the power access switch are all deployed in any one of the forms of relay switches, MOSFET switches or a hybrid form of relays and MOSFET switches.

[0018] Preferably, forming a series or parallel type hot standby redundancy according to different connection modes of the power distribution unit includes:

[0019] When the power distribution units are connected in series, the current passing through each power distribution unit is the same, and the input voltage varies according to the load. When a single power conversion unit has a short - circuit, it does not act and does not affect the normal operation of other power conversion units. When an open - circuit occurs, the power distribution unit shorts its input port;

[0020] When the power distribution units are connected in parallel, the output voltages of the power distribution units are the same, and the input current varies according to the load. When a single power conversion unit has an open - circuit, it does not act and does not affect the normal operation of other power conversion units. When a single power conversion unit has a short - circuit fault, the power distribution unit cuts it off.

[0021] Preferably, the cooperative current sharing algorithm balances power dissipation and includes:

[0022] In the series mode, the power distribution unit with a lower given current will bear more power, have a lower duty cycle, and a higher input voltage. The current sharing algorithm is: I real = I set - duty × C duty + V in × C in ; where I real is the given current actually used for closed-loop calculation, I set is the target given current value sent by the shore base station, duty is the duty cycle of the power distribution unit itself, C duty is the duty cycle current sharing coefficient, V in is the input voltage of the power distribution unit itself, and C in is the input voltage current sharing coefficient.

[0023] Preferably, in the parallel mode, the power distribution unit with a higher given current will bear more power, have a higher duty cycle, and a higher input current. The current sharing algorithm is: where I real is the given current actually used for closed-loop calculation, I set is the target given current value sent by the shore base station, duty is the duty cycle of the power distribution unit itself, C duty is the duty cycle current sharing coefficient, I p is the total current dissipated by the constant power unit, I in is the input current of the power distribution unit itself, and C in is the input current current sharing coefficient.

[0024] Preferably, the power conversion unit includes: an auxiliary power supply circuit, a sampling circuit, a main control circuit, a power conversion circuit, and a communication circuit; where

[0025] The auxiliary power supply circuit is used to supply electrical energy to the subsequent control circuit;

[0026] The sampling circuit is used to collect the input and output current and voltage, the temperature and pressure inside the cabin;

[0027] The main control circuit is used to perform autonomous fault judgment and / or according to the received fault isolation instruction, by controlling the working state of the power conversion circuit and the specific actions of the power distribution unit, to isolate the damaged power conversion unit and perform fault protection;

[0028] The power conversion circuit is used to convert the direct current of the underwater power supply and supply it to the balanced load;

[0029] The communication circuit is used to communicate with the control system, and can report its own status in real time, and can also receive the working instructions of the control system. It communicates with the shore base station through the connection box, reports its own parameters to the shore base station in real time, and receives the fault isolation instruction to notify the main control circuit to isolate the damaged power conversion unit.

[0030] Preferably, the power conversion circuit adopts a full-bridge circuit, a resonant circuit, a multi-level circuit, a Buck circuit or a Boost circuit.

[0031] Preferably, the startup process of the power balance module includes:

[0032] The underwater power supply is powered on and outputs, and the power balance module starts the auxiliary power supply;

[0033] The power distribution unit performs self-check, judges the fault status, and the power distribution unit connects or disconnects the power conversion unit from the main power circuit;

[0034] According to the default setting, the power distribution unit slowly releases the given value to the maximum power point, the power balance module works at full load, and the underwater power supply works at full load.

[0035] The shore base end issues the given current parameter according to the actual load demand;

[0036] According to the control requirement, the power distribution unit slowly reduces the given power point, and while ensuring the actual demand, maintains the low-power operation of the underwater power supply;

[0037] The connection box opens the load port according to the scientific mission requirements, and the power conversion unit dynamically balances its own dissipated power according to the actual load consumption power;

[0038] The shutdown process of the power balance module includes:

[0039] The connection box controls the load port to close, and the power conversion unit maintains power balance;

[0040] The underwater power supply shuts down, and the power balance module shuts down due to power failure.

[0041] Preferably, the board is deployed inside the cylinder of the power balance module. The balance load can be integrated with the existing cylinder or independently set in the form of a separate cylinder according to the actual power demand;

[0042] The power balance module selects different quantities according to the reliability requirements.

[0043] Compared with the prior art, the advantages of the present invention are:

[0044] 1. The power balance module applicable to the subsea observation network proposed by the present invention can select different numbers and different forms of redundant forms of multi-function power conversion units according to reliability requirements, and form power balance among multiple units, eliminating the risk of single-point failure and improving the reliability of the power supply network.

[0045] 2. The power balance module applicable to the subsea observation network proposed by the present invention can adjust the operating power. The power balance module can solve the problem of long-term full-load operation of underwater power supplies. The shore base station can adjust the operating power of the power balance module according to the actual load power, reduce the dissipation of ineffective heat, reduce the output power of the underwater power supply, reduce heat generation and port voltage, and reduce the ground voltage of the submarine cable, effectively ensuring the long-term stable operation of the power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is the structural block diagram of the power balance module applicable to the subsea observation network of the present invention;

[0047] Figure 2 is the internal unit structure diagram of the power balance module;

[0048] Figure 3 is the internal structure diagram of the balanced load;

[0049] Figure 4 is the connection relationship diagram of the series redundancy mode;

[0050] Figure 5 is the connection relationship diagram of the parallel redundancy mode;

[0051] Figure 6 is the start-up process of the series redundancy;

[0052] Figure 7 is the start-up process of the parallel redundancy. DETAILED DESCRIPTION OF THE INVENTION

[0053] A power balance module applicable to the subsea observation network of the present invention is used to solve the problem of constant power stable operation of underwater power supplies. As shown inside Figure 1 it is composed of a power conversion unit, a power distribution unit, a sampling unit and a balanced load.

[0054] Among them, the power conversion unit, the power distribution unit and the sampling unit exist in the form of circuit boards and are respectively deployed inside the corresponding module cylinders. The balanced load can be integrated with the existing cylinder or independently set in the form of a separate cylinder according to the actual power demand.

[0055] The basic working process of the present invention is that the sampling unit collects the total input current of the module, and the power conversion unit extracts power from the underwater power supply quantitatively and dissipates it through the balanced load. When the actual load is connected, the power conversion unit reduces the converted electric energy in real time, reduces the dissipated power of the balanced load, ensures that the total input current is maintained at a constant value, and ensures that the output power of the underwater power supply is balanced.

[0056] The internal structure of each unit of the power balance module is as Figure 2 shown:

[0057] The power conversion unit can extract power from the underwater power supply quantitatively and supply it to the balanced load for dissipation. It is internally composed of an auxiliary power supply circuit, a sampling circuit, a main control circuit, a power conversion circuit, and a communication circuit. The auxiliary power supply circuit provides electrical energy for the subsequent control circuit. The sampling circuit collects the current and voltage of the input and output, as well as information such as the temperature and pressure inside the cabin. The main control circuit is responsible for controlling the working state of the power conversion circuit and the specific actions of the power distribution unit. When multiple units operate redundantly, it can independently perform fault judgment and carry out fault protection. The power conversion circuit converts the direct current of the underwater power supply and supplies it to the balanced load for power dissipation, and can adopt but is not limited to full-bridge circuits, resonant circuits, multilevel circuits, Buck circuits, Boost circuits, etc. The communication circuit is responsible for communicating with the control system, can report its own status in real time, and can also receive the working instructions of the control system.

[0058] The power distribution unit can realize the distribution of the direct current output by the underwater power supply to the power conversion unit and isolate it when the power conversion unit fails, which is controlled by the main control circuit. It is internally composed of a power access switch, a short-circuit switch, and a short-circuiting switch to form a switch network. The power access switch connects the power conversion unit to the DC bus; the short-circuit switch is used to connect each power conversion unit in series in turn; the short-circuiting switch is used to short-circuit the input port of the power conversion unit.

[0059] Various switches can be flexibly configured according to actual needs. In the parallel mode, the short-circuit switch and the short-circuiting switch can be not configured; in the series mode, the power access switch can be not configured.

[0060] The above-mentioned various switches can be deployed in the form of relay switches, MOSFET switches, relay and MOSFET hybrid switches, etc.

[0061] The sampling unit can collect the total current input to the power balance module, and it is internally composed of a sampling resistor or a Hall element. The collected parameters are supplied to each power conversion module for closed-loop control.

[0062] The function of the balanced load is to receive the electric energy output by the power conversion unit, convert it into heat energy and dissipate it through seawater, as Figure 3The internal structure diagram of the balanced load is shown. It is composed of a resistor network and is independent according to the number of power distribution units. It can be deployed in the same cylinder as the constant power board or exist as an independent cylinder.

[0063] Multiple power conversion units of the present invention can form series and parallel redundant backups according to different connection methods of the power distribution units:

[0064] The series redundant working mode is as Figure 4 shown. The power distribution units are connected in series. The current I passing through the module p is consistent, and the input voltage varies according to the load. In this redundant mode, when a single module has a short circuit, it does not affect the normal operation of other modules and no action is required. When a single module has an open circuit, it is necessary to control the power distribution unit to short-circuit its input port.

[0065] The parallel redundant working mode is as Figure 5 shown. The power distribution units are connected in parallel. The input voltages of the modules are consistent, and the input current varies according to the load. In this redundant mode, when a single module has an open circuit, it does not affect the normal operation of other modules and no action is required. When a single module has a short circuit fault, it is necessary to control the power distribution unit to cut it off.

[0066] Multiple power conversion units cooperate with the current sharing algorithm to balance power dissipation and form a hot standby redundancy, which can ensure that the power balance module remains in normal operation after any half of the power conversion units are damaged.

[0067] The set working point of the present invention can be adjusted to solve the problem of long-term full load of the underwater power supply. The power balance module can communicate with the shore base station through the communication circuit via the connection box. By reporting its own parameters in real time, it helps the shore base equipment understand the current working state. The shore base equipment can issue the target working current. When the actual load power is small, by reducing the target working current, the overall power of the underwater power supply can be reduced and the port voltage can be lowered. When multiple units are operating in series and parallel, a fault isolation instruction can be issued to manually isolate the damaged power conversion unit to ensure the normal operation of the power balance module.

[0068] The technical solution of the present invention will be described in detail below with reference to the drawings and embodiments.

[0069] Embodiment 1

[0070] A power balance module applicable to a submarine observation network of the present invention, as Figure 1 shown, is composed of a power balance module board and a balanced load. The constant power board includes a power conversion unit, a power distribution unit, and a sampling unit.

[0071] The input side of the power balance module is connected to the output of the power conversion module of the underwater power supply, and its output is connected to the input port of the balanced load. The power distribution unit directly outputs the direct current output by the underwater power supply to the subsequent junction box. The startup logic of the power balance module is as follows:

[0072] 1. When the underwater power supply is powered on and outputs, the auxiliary power of the power balance module starts.

[0073] 2. The main control MCU performs self-check, judges the fault status, and controls the power distribution unit to connect or disconnect the power conversion unit from the main power circuit. Among them, the main control MCU is the controller of the main control circuit of the power distribution unit.

[0074] 3. The MCU releases the given value slowly to the maximum power point according to the default setting. The power balance module works at full load, and the underwater power supply works at full load.

[0075] 4. The shore-based equipment issues the given current parameters according to the actual load demand.

[0076] 5. The MCU slowly reduces the given power point according to the control requirement, while ensuring the actual demand, maintaining the low-power operation of the underwater power supply.

[0077] 6. The junction box opens the load port according to the scientific mission requirements, and the power balance module dynamically balances its own dissipated power according to the power consumed by the actual load.

[0078] The shutdown logic of the power balance module is as follows:

[0079] 1. The junction box controls the load port to close, and the power balance module maintains power balance.

[0080] 2. The underwater power supply shuts down, and the constant power unit shuts down due to power loss.

[0081] The power balance module runs at the maximum power point by default, which can ensure that when there is a problem with the communication circuit, the underwater power supply can provide the maximum power output to ensure the normal operation of the actual load. When the system runs stably, the shore-based equipment issues the given parameters, including the target current, change slope, working mode. The constant power unit slowly adjusts the power setting point to the target point according to the given requirements, reducing the voltage at the underwater power supply port to achieve the purpose of power derating.

[0082] The internal structure of the power balance module is as Figure 2 shown:

[0083] The power conversion unit can quantitatively extract power from the underwater power supply and supply it to the balanced load for dissipation. It consists of an auxiliary power supply circuit, a sampling circuit, a main control circuit, a power conversion circuit, and a communication circuit inside. The auxiliary power supply circuit provides electrical energy for the subsequent control circuit. The sampling circuit collects the current, voltage, cabin temperature, pressure and other information of the input and output. The main control circuit is responsible for controlling the working state of the power conversion circuit and the specific actions of the power distribution unit. When multiple units operate redundantly, it can independently perform fault judgment and carry out fault protection. The power conversion circuit converts the direct current of the underwater power supply and supplies it to the balanced load for power dissipation. The communication circuit is responsible for communicating with the control system, reporting its own status in real time, and also receiving the working instructions of the control system.

[0084] The power distribution unit can realize the distribution of the direct current output by the underwater power supply to the power conversion unit and isolate it when the power conversion unit fails, which is controlled by the main control circuit. It consists of a power access switch, a short-circuit switch, and a short-circuiting switch to form a switch network inside. The power access switch connects the power conversion unit to the DC bus; the short-circuit switch is used to connect each power conversion unit in series in turn; the short-circuiting switch is used to short-circuit the input port of the power conversion unit.

[0085] All kinds of switches can be flexibly configured according to actual needs. In the parallel mode, the short-circuit switch and the short-circuiting switch can not be configured; in the series mode, the power access switch can not be configured.

[0086] All kinds of switches can be deployed in the form of relay switches, MOSFET switches, relay and MOSFET hybrid switches, etc.

[0087] The sampling unit can collect the total current input to the power balance module, which consists of a sampling resistor or a Hall element inside. The collected parameters are supplied to each power change module for closed-loop control.

[0088] The function of the balanced load is to receive the electrical energy output by the power conversion unit, convert it into heat energy and dissipate it through seawater, such as Figure 3 It is composed of a resistor network and is independent according to the number of power distribution units. It can be deployed in the same cylinder as the constant power board or exist as an independent cylinder.

[0089] The basic constant power adjustment strategy is as follows:

[0090] Assume that the voltage at the output port of the underwater power supply is V o , and the total output power to be maintained is P o , then the output current of the underwater power supply should be I o = P o / V o . Among them, I o is the current I l of the actual scientific load and the current I consumed by the power balance modulep The sum

[0091] The current consumed by the power balance module (taking a single power conversion unit as an example). Where V p is the output voltage of the power conversion unit, R is the value of the balanced load resistor, and η is the conversion efficiency of the power conversion unit. When the output voltage V of the power conversion unit is increased p , the current I consumed by the power balance module p rises, and the power conversion unit consumes more energy.

[0092] The power balance module continuously collects the output current I of the underwater power supply o , and when the current I of the scientific load l rises, the output voltage V of the power conversion unit is reduced p , thereby reducing the dissipated current I p , and maintaining the consistency of the output current of the underwater power supply.

[0093] To solve the problem that the power balance module has insufficient redundancy and there is a risk of single-point failure, the modular design of the present invention can configure multiple power conversion units in series-parallel redundancy to improve the system reliability. An equal current sharing algorithm is used between multiple power conversion units to ensure power balance, achieving the functions of hot standby and derating:

[0094] The startup process of series redundancy is as Figure 6 shown: After the module is started, the main control unit opens the given limit. If an open circuit occurs in a certain power conversion unit, the impedance at the open circuit increases, and the impedance of other units decreases. Each power conversion unit performs self-fault determination, and the power distribution unit short-circuits the power conversion unit that has not reported its normal state, ensuring that the series circuit between the power conversion units remains normal.

[0095] The startup process of parallel redundancy is as Figure 7 shown: After the module is started, the fault count is incremented by 1. When the count limit is not reached, the power conversion unit is connected. If the power conversion unit does not fail, the fault count is cleared. If a failure occurs, the fault count remains unchanged. After multiple power-on operations, when the count limit is reached, this power conversion unit is permanently removed and no longer connected to the power circuit.

[0096] To solve the problem of output imbalance between power conversion units during redundant operation of multiple power conversion units, the present invention uses an equal current sharing algorithm to actively change the actual given current of this unit to ensure power balance between modules.

[0097] In the series mode, the power distribution unit with a lower given current will bear more power, its duty cycle is lower, and the input voltage is higher. The equal current sharing algorithm is: I real = I set - duty × Cduty +V in ×C in 。Among them, I real is the given current actually used for closed-loop calculation. I set is the target given current value sent by the host computer, duty is the duty cycle of the power distribution unit itself, and C duty is the duty cycle current sharing coefficient, and V in is the input voltage of the power distribution unit itself, and C in is the input voltage current sharing coefficient.

[0098] In the parallel mode, the power distribution unit with a higher given current will bear more power, with a higher duty cycle, a higher input current, and the current sharing algorithm is: Among them, I real is the given current actually used for closed-loop calculation. I set is the target given current value sent by the host computer, duty is the duty cycle of the power distribution unit itself, and C duty is the duty cycle current sharing coefficient, I p is the total current dissipated by the constant power unit, I in is the input current of the power distribution unit itself, and C in is the input current current sharing coefficient.

[0099] It should be noted that in the embodiments of the above system, the various modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional modules are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0100] Innovation points:

[0101] 1. Support series-parallel redundancy forms, and redundant schemes can be selected according to actual needs. Each unit inside the module operates in a hot standby form and can respond to load changes in a timely manner.

[0102] 2. The operating power is variable. According to the actual load operating requirements, the operating power of the power balance module can be adjusted to reduce the heat generation of the underwater power supply, lower the port voltage of the underwater power supply, and improve the operating life of the power supply network.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A power balancing module suitable for a submarine observation network, the input side of which is connected to a main power conversion module of an underwater power supply, and the output end is connected to a subsequent junction box, characterized in that: The power balancing module includes: a sampling unit, a power distribution unit and a plurality of power conversion units deployed on a board, and a balanced load, wherein: The sampling unit is used to collect the total current of the constant voltage output of the main power conversion module of the underwater power supply, and output the collected parameters to each power conversion module for closed-loop control; The power distribution unit is used to distribute the total current output by the underwater power supply to each power conversion unit, and to isolate a power conversion unit when it fails; The multiple power conversion units are used to form series or parallel hot standby redundancy according to different connection modes of the power distribution units, and cooperate with the current sharing algorithm to balance power dissipation; each working power conversion unit extracts power from the underwater power supply in a quantitative manner and supplies it to the balanced load for dissipation. When the actual load is connected, the converted electric energy is reduced in real time, the dissipated power of the balanced load is reduced, and the output power of the underwater power supply is ensured to maintain balance; The balancing load is used to receive the electric energy output by the power conversion unit, convert it into heat energy and then dissipate it through seawater.

2. The power balancing module suitable for a submarine observation network according to claim 1, characterized in that: The sampling unit adopts a sampling resistor or a Hall element.

3. The power balancing module suitable for a submarine observation network according to claim 1, characterized in that: The power distribution unit uses a switch network to realize the distribution function. In the series mode, the switch network is composed of a short-circuit switch and a short-circuit switch. In the parallel mode, the switch network is composed of a power access switch, wherein: The short-circuit switch is used to connect the power conversion units in series in sequence; The short-circuit switch is used to short-circuit the input port of the power conversion unit; The power access switch is used to connect the power conversion unit to the DC bus; The shorting switch, the short-circuit switch and the power access switch are all deployed as any one of relay switches, MOSFET switches or relay and MOSFET hybrid switches.

4. The power balancing module suitable for a submarine observation network according to claim 3, characterized in that: The method of forming a series or parallel hot standby redundancy according to different connection modes of the power distribution units includes: When the power distribution units are connected in series, the current passing through each power distribution unit is consistent, and the input voltage changes according to the load. When a single power conversion unit is short-circuited, it will not operate and will not affect the normal operation of other power conversion units. When an open circuit occurs, the power distribution unit will short-circuit its input port; When the power distribution units are connected in parallel, the output voltages of the power distribution units are consistent, and the input current changes according to the load. When a single power conversion unit is open-circuited, it will not operate and will not affect the normal operation of other power conversion units. When a short-circuit fault occurs in a single power conversion unit, it will be cut off by the power distribution unit.

5. The power balancing module suitable for a submarine observation network according to claim 4, characterized in that: The coordinated current sharing algorithm balances power dissipation, including: In series mode, the power distribution unit with lower given current will bear more power, with lower duty cycle and higher input voltage. The current sharing algorithm is: I real =I set -duty×C duty +V in ×C in ; Among them, I real is the given current actually used for closed-loop calculation, I set is the target given current value sent by the shore base station, duty is the duty cycle of the power distribution unit itself, C duty is the duty cycle current sharing coefficient, V in is the input voltage of the power distribution unit itself, C in is the input voltage current sharing coefficient.

6. The power balancing module suitable for a submarine observation network according to claim 4, characterized in that: In parallel mode, the power distribution unit with higher given current will bear more power, with higher duty cycle and higher input current. The current sharing algorithm is: Among them, I real is the given current actually used for closed-loop calculation, I set is the target given current value sent by the shore base station, duty is the duty cycle of the power distribution unit itself, C duty is the duty cycle current sharing coefficient, I p is the total current dissipated by the constant power unit, I in is the input current of the power distribution unit itself, C in is the input current sharing coefficient.

7. The power balancing module suitable for a submarine observation network according to claim 1, characterized in that: The power conversion unit includes: an auxiliary power supply circuit, a sampling circuit, a main control circuit, a power conversion circuit and a communication circuit; wherein, The auxiliary power supply circuit is used to provide power to the subsequent control circuit; The sampling circuit is used to collect input and output current and voltage, cabin temperature and pressure; The main control circuit is used to perform autonomous fault judgment and / or control the working state of the power conversion circuit and the specific actions of the power distribution unit according to the received fault isolation instruction to isolate the damaged power conversion unit for fault protection; The power conversion circuit is used to convert the direct current of the underwater power supply and supply it to the balanced load; The communication circuit is used to communicate with the control system, can report its own status in real time, and can also receive work instructions from the control system. It communicates with the shore base station via the docking box, reports its own parameters to the shore base station in real time, and receives fault isolation instructions to notify the main control circuit to isolate the damaged power conversion unit.

8. The power balancing module for a submarine observation network according to claim 7, characterized in that: The power conversion circuit adopts a full-bridge circuit, a resonant circuit, a multi-level circuit, a Buck circuit or a Boost circuit.

9. The power balancing module for a submarine observation network according to claim 1, characterized in that: The startup process of the power balancing module includes: The underwater power supply is powered on and output, and the power balancing module starts the auxiliary power; The power distribution unit performs self-checking and determines the fault status, and the power distribution unit connects the power conversion unit to or cuts it out of the main power circuit; According to the default settings, the power distribution unit slowly releases the given power to the maximum power point, the power balance module works at full load, and the underwater power supply works at full load; The shore-based end sends down given current parameters according to actual load requirements; According to the control requirements, the power distribution unit slowly reduces the given power point, maintaining the low-power operation of the underwater power supply while ensuring the actual demand; The docking box opens the load port according to the scientific mission requirements, and the power conversion unit consumes power according to the actual load and dynamically balances its own dissipated power; The shutdown process of the power balancing module includes: The docking box controls the load port to close, and the power conversion unit maintains power balance; The underwater power supply is shut down, and the power balancing module is powered off and shut down.

10. The power balancing module applicable to the seabed observation network according to claim 1, characterized in that: The board is deployed inside the cylinder of the power balancing module, and the balancing load can be integrated with the existing cylinder or independently set in the form of a separate cylinder according to the actual power demand; The power balancing modules are selected in different quantities according to reliability requirements.

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